This should work, right? Specifically the PE4L-PM060A... I know mPCIe is just x1 but does it scale with PCIe versions, would a Hasewell NUC have mPCIe 3.0? That would be what, 1000MB/s? Maybe you could run a GT640 on that without losing much performance? You can grab NUC boards for pretty cheap (that one's Ivy) and other than the power supply I think you'd be all set...

I read up on all the folks doing eGPU stuff with adapters like this (mostly express card), but no one trying any mods with something like a NUC, BRIX, etc... Of course if Gigabyte would just release a Kaveri BRIX then it wouldn't really matter, but it still might be fun...

Based on what I've read at Notebook Review, the PM060A should totally work. x1 would be enough to give you decent performance on a GT640 or similar. You might get some stuttering in certain games/scenes but it'll still be way ahead of the integrated GPU. Based on the scaling analyses I've read you should get about 75% the performance of a x16 port, give or take 20%. The mPCIe slot is PCIe 2.0 right?

I never was able to figure that out. I would think it is at least 2.0 for Ivy though, maybe 3.0 on Haswell - I don't know how the support for the chip translates to support on the board/the smaller form factor connector...

I think it depends on the PCIe source. The GPU might be on a 3.0 PCIe port (if it's a dedicated GPU) but peripherals are more likely to be on a 2.0 or even 1.1 in some cases. But I'd wager 2.0 for most x1 lanes these days.

I personally wouldn't try this without consulting some manufacturers first, just because the slot fits doesn't mean the hardware will actually work as expected. I like me some good hardware hacking but this seems like way more trouble than it's worth--similar cost and volume gets a low-profile mini-ITX system with notably better overall performance than a NUC.

If it is 1x slot coming from the chip set it is 2.0 since sandy I believe....I think I just read even the new Z97 motherboards chip set is still PCIE 2.0.....But if it is coming from the CPU PCIE lanes it is 2.0 for sandy and 3.0 since ivy bridge.

Also like Novus said I would price out a M-atx setup even atx before I built a NUC that always seem to be expensive and you are usually limited to a low power low speed dual core. At least with Micro ATX or ATX or ITX you can upgrade the cpu if you ever need to or just get a fast CPU to boot.